The HUD is a flight auxiliary instrument widely applied on aircrafts, which uses the principle of optical reflection to project the important navigation information, recreation information on the lens in front of the pilot, such that the pilot can be informed of the displayed information of the meters and navigator without lowering head to check, such that the attention of the pilot is prevented from being interrupted by lowing head to check and losing control of the status, thereby improving the safety of the flight.
Currently, an increasing number of HUDs are applied in the vehicle industry. Most conventional an on-board HUDs appear in a rectangular block structure and is placed in front of a driver to display part of the driving information, still, the conventional an on-board HUDs also block a part of the driving view of the driver, which results that the safety of the driving as well as the experience of the user are compromised.